High speed circuit design for quantum physics light sensing

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[Limpkin] designs circuits for a living. This board is one of his recent projects, and although his skills are light years ahead of our own experiences, he did a pretty good job of explaining how he put this board together.

He was tasked with measuring the light intensity of two photodiodes. The expected impulses picked up by those components will be less than a nanosecond in duration, putting some special design constraints upon him. To register this signal he’s using three cascading op-amps per input. To ward off false readings from RF interference he also designed in the shielding which you see surrounding the majority of the circuit.

His package choice for the THS3202 op-amps is quite interesting. He didn’t go with the footprint that includes a thermal pad to dissipate heat because he didn’t want to interrupt the ground plane on the underside of the board. To keep the parts from melting he added an aluminum spacer that contacts the top of the package, then a heat sink that covers the entire shield frame. In a future revision he figures he’ll move to a four-layer board so that the can opt for the MSOP package that does the work for him.

Robot juggler sure handles a lot of balls

This robot juggler, pictured above during its appearance at Amper 2010, can keep five balls in the air at once. It was designed by the Department of Control Engineering at the Czech Technical Institute in Prague. We know it doesn’t look like much in that still image, but the two videos embedded after the break are pure gold.

To arms on vertical tracks do the juggling. They can move up and down on said tracks, and circular grippers attached to each can pivot horizontally. A third actuator resides at the bottom of the machine, collecting any balls that might drop, and launching them back into the realm of the juggling hands. A high-speed camera facilitates object tracking in much the same ways that it’s been used for quadcopter control.

The objects being thrown around in that protective enclosure are billiards balls. We guess the added mass helps to dampen any small irregularities in the throw or the catch.

[Read more...]

Flip-book style digitization

This method of book digitization allows you to scan an entire book by fanning through the pages. It uses a high-speed camera that captures 500 frames per second to get a good look at each page. Processing software isolates each pages, analyzes any curve in the paper due to the flipping, and smooths out the image for better optical character recognition results. The greatly reduces the time it takes to digitize a book, even compared to setups that automatically flip pages.

[Thanks Erico]

Axe your camera (again!)

[Maurice] let us know that his latest photography tool for hackers, the Camera Axe 3.0, is now available. The original allowed you to trigger a high-speed flash and camera from a multitude of sensors, including light and sound. The new one does all that, but also: allows multiple cameras or multiple flashes, clean up of software to make it more user adaptable, and the best (arguably the most important) part – cheaper components! All that and more under the Creative Commons that we do love so much. Keep up the amazingly detailed and just pure awesome work [Maurice].

Laser triggered photography

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Popped balloons or bullets fired into apples, anyone can photograph with a quick sound based camera rig. Lasers have been used forever in motion detection. And even door bell chimes have been used before for remote camera shutter releases. No, [SaskView] wanted to go further and created his Laser Triggered High-Speed Photography setup, to photograph (of all things) milk splashes. We liked the simplicity of the project however;  requiring no programmed microchips or overly complicated circuitry – rather he took a quick trip to the local dollar shop, used the amazing CHDK firmware, and he produced perfect results every time.

[Update: CHDK, not CHKD firmware. My mind must be elsewhere. Thanks jbot and agent smith]

Amazing robot dexterity

Ishikawa Komuro Laboratories are doing some amazing stuff with robots right now. The video above starts out looking like a clumsy and somewhat failed attempt at dribbling a ping pong ball. Once it goes into slow motion however, we see the true action. This robot is dribbling that ball amazingly. Utilizing 1000 FPS cameras, it readjusts and hits the ball on every bounce. As the ball drifts out of the reach of the bot, suddenly we are struck with the lifelike motion.  Personification can be a fleeting thing, appearing so strongly as the little bot tries in vain to reach for that ball, then disappearing again an instant later. If you really want to see some personification worthy of the crab fu challenge, check out their tool manipulation by a multi fingered hand video.

[via BotJunkie]

The camera axe

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The Camera Axe is an open source system for doing high speed camera triggering. You know all those pictures people get of balloons popping or drops of water in mid splash? This is how they do it. The system has light sensors and sound sensors to help get the timing just right. It can trigger your camera and the flash to capture images at just the right moment. There are a lot of picture examples on the site as well as a full schematic and parts list. Not too bad for roughly $100.